Robot spacecraft in zero-gee pumping shocker

Two unmanned space platforms have autonomously come together 300 miles above the earth, carrying out a "pump fluid transfer" in a milestone for robot sex automated satellite servicing.

A Boeing Autonomous Space Transport Robotic Operations (ASTRO) vehicle and a NextSat serviceable-satellite demonstrator were launched together aboard an Atlas rocket on 8 March. Following launch there were software problems which caused difficulties in orienting the machines, but these were overcome by ground engineers and the two spacecraft duly separated.

The mating and fluid-transfer demonstration was achieved two days ago, according to a Boeing release. The NextSat received 32lb of pressurised hydrazine from ASTRO, and a further 17lb by pumping.

Rather than (deeply) specialist robot smut, the quarter-billion-dollar Orbital Express programme is intended to demonstrate that satellites can be refuelled and serviced by autonomous systems, which could greatly extend their useful life span on some platforms.

In particular, the US military's extensive network of spy satellites could find this useful. Surveillance birds need to change orbit fairly frequently so as to get a good look at locations of interest, and each orbit change uses up thruster fuel. Once all a satellite's manoeuvring juice is gone, it has tended to become useless.

It's no surprise, then, that the Defence Advanced Projects Research Agency (DARPA) is heavily involved in Orbital Express. But NASA is in there too, as ordinary civilian space efforts could also find robot satellite fill-ups useful. Some funding has also come from corporate sources, with Boeing stating last year that it has contributed "millions...a very significant fraction of the overall cost". Boeing's ASTRO service-bot can do more than just squirt thruster fuel. During this week's demo, it successfully plugged a battery into NextSat using a robotic arm.

At present, ASTRO operates under a low level of autonomy, needing to ask for approval to proceed (ATP) fairly frequently, not unlike a Windows computer. According to Boeing, however, "future demonstrations will require fewer ATPs, allowing Orbital Express to conduct flight activities with increased autonomy. At the highest autonomy levels, no ATPs are required".